The detention, a very unusual move for such a high-level figure, has dominated French news broadcasts, and comes at a time when news of a possible political comeback by the hard-driving 59-year-old has been floated by his Union for a Popular Movement (UMP) party.

Sarkozy, who spent nearly a day in custody answering questions on his 2007 presidential campaign, told TF1 TV and Europe-1 radio he was "profoundly shocked" by his 15-hour detention.